The invention relates to medical instruments having a jaw or jaws for clamping, grasping, or holding medical devices and/or portions of an individual's anatomy.
Conventional medical instruments (needle holders, forceps, etc.) may be used by a physician to manipulate the handles to hold and work the grasping jaws for various medical procedures. Conventional forceps and needle holders are fabricated from a pair of rigid parts each having a jaw at one end and a handle with a ring at the other end. The two parts are mounted together to form a scissors-like instrument. The two parts are pivotally secured behind the pair of jaws. There is a finger ring and a thumb ring at the distal end of each handle. The physician places his thumb in one ring and his index finger in the other ring to control and manipulate the tool or instrument. He can squeeze the two rings together with his thumb and finger to cause the jaws to clamp down. The conventional forcep requires squeezing of the handle while simultaneously manipulating the forcep. Some instruments have engageable snap together locking means on the pair of handles and towards the rings to lock the jaws shut by locking the pair of handles together. It is usually a snap connection. The lock will engage when sufficient force is supplied by the finger and thumb to press the rings together. The lock will disengage when sufficient force is applied to spread apart the rings.
The disadvantage of this type of locking instrument is that substantial side force must be used to unlock the handles. Sometimes, this requires the use of two hands. If one hand is used to spread apart the rings, the forceps may suddenly move laterally as the rings disengage, potentially causing collateral damage or puncture of a delicate organ or blood vessel. Physicians often need the other hand for holding onto the skin or organ and cannot spare that hand to help to disengage the clamped instrument.
There is a need for medical instruments with an improved locking arrangement which allows the physician to lock and unlock the instrument using only one hand, and without imposing any side-to-side motion of the instrument as the jaws unlock.
Medical instruments come in various sizes and are used for particular medical procedures. Thus, a medical instrument must be capable of clamping onto a variety of objects including, but not limited to surgical needles, vessels, and/or organs. There is thus a need for a tension adjustment for the jaws of the medical instrument. The tension must be adjustable with only one hand.